// 将其它数据转换为 boolean 值

// 将 Boolean 当作普通函数使用时，
// 用于将其它数据转换为 boolean 值(原始类型)

let x = Boolean();
console.log( x , typeof x );

x = Boolean( null );
console.log( x , typeof x );

x = Boolean( undefined );
console.log( x , typeof x );

x = Boolean( 0 );
console.log( x , typeof x );

x = Boolean( '' );
console.log( x , typeof x );

x = Boolean( NaN );
console.log( x , typeof x );

x = Boolean( false );
console.log( x , typeof x );

x = Boolean( [ ] );
console.log( x , typeof x );

x = Boolean( { } );
console.log( x , typeof x );